This application proposes experiments to study mechanisms by which the ciliary epithelium and aqueous outflow channels maintain intraocular pressure. Physiologic and pharmacologic influences, especially of the adrenergic nervous system, on aqueous humor formation and aqueous outflow, will be studied. Outflow resistance will be determined by constant pressure perfusion. Studies of the uptake, binding and degradation and localization of norepinephrine and its analogs involve labelling techniques, liquid scintillation counting and column chromatography. Assays for enzymes degrading catecholamines will require labelled substrates. Studies of the disturbed barrier include an extensive physiologic and pharmacologic investigation of the mediators for the increase in permeability after commonly used ocular agents.